Extension-table slide



(No Model.)

H. 0. HALL.

EXTENSION TABLE SLIDE.

N0. 359,782 Patented Mar. 22, 1887.

QFHML UNITED STATES PATENT rricE.

HENRY O. HALL, OF ST. PAUL, MINNESOTA.

EXTENSlON-TABLE suns.

SPECIFICATION forming part of Letters Patent No. 359,782, dated March22, 1887.

Application tiled July 2*, with Serial No. 209,282. (No model.)

To (LZZ whom it may concern:

Be it known that I, HENRY O. HALL, acitizen of the United States,residing at St. Paul, in the county of Ramsey and State of Minnesota,have invented certain Improvements in Extension-Table Slides, of whichthe follow ing is a specification.

This invention relates to improvements in that class of extension-tablesin which extension-bars are used having grooves upon their upper andlower edges, with metallic plates or slides that are secured to the topand bottom of both bars, the plates that are secured to each barprojecting over the other bar and being provided with ribs that travelin grooves therein. An example of this class of slides is shown in thepatent to Elisha Mets, No. 36,496, granted September 16, 1862.

Heretofore it has been customary to secure the metal plates to the railsby screws that were passed through each plate near one edge thereof.This manner of securing the plates has always been open to objections,as the screws could not be set into the wood with sufficient accuracy tobring them into corresponding positions upon the two edges of the rail,and one plate would often cant or twist in one direction and the otherin another. Moreover, the plates were held by short screws only, andthey were placed so near the edge of the rail as to frequently split thewood,thus making the slide insecure and liable to get out of place.Again, in the old slide the screws werepla-ced close to one of the ribsupon the plate, and as there was no bearing for the plate beyond therib, and the groove was often deeper than the rib, the edge of the platewas often drawn into the groove, throwing the other edge outward, sothat the plate could not bear firmly on the bar. I seek to overcomethese objections by providing the slides with a common securing meansthat draws them firmly against the top and bottom of the bar. I alsoprovide the slide with a bearingflange that extends beyond the edge ofthe slide, and keeps it from being brought unevenly against the bar.

In the accompanying drawings, forming part of this specification, Figure1 is a plan of two of the extensioirbars with the slides securedthereto. Fig. 2 is a section on line X X of Fig. 1. Fig. 3 is a sectionon line Y Y of Fig. 1,

showing the plates held by screws. Fig. 4 is an under side View of oneof the metal plates.

Fig. 5 is a similar view ofa plate having two bearingflanges. Fig. 6 isan end view of the plate.

The bars A are of ordinary construction. They are provided upon the topand bottom, near their edges,with the longitudinal grooves B. The shortmetallic plates 0 are placed on the top and bottom of each bar,'andproject beyond its edge and over the top and bottom of the next bar.Each plate is provided with a rib, D, that rests in the groove 13,thereby holding the bars together.

A hole is made through the bar, and a bolt is passed through one of theplates, through the bar, and through the other plate, and is providedwith a nut, F. By this means both plates are drawn firmly against thebar and held in corresponding positions.

The advantages from this construction are that both plates are equallyand firmly drawn against the wood, there is no danger of splitting thewood, and each plate serves as a washer for the bolt, and the two metalplates, therefore,

take nearly all the strain off the bar. The bars are preferablyrecessed, so as to allow the plates to set below their surface.

I prefer to provide each slide with a rib, 1), near its opposite edge,and to set this rib into the groove in the bar to which the plate issecured, and to provide a bearing-flange, G, that projects beyond therib D and bears upon the wood on the other side of the groove. Thisflange keeps the edge of the plate from being drawn into the groove. Thebolt-hole H is formed in the plate, preierably in about the line of therib D. The plate may, if preferred, be provided with more than oneflange G, as shown in Fig. 5. The plates having thebearjug-flanges G maybe secured to the bars by screws E, as shown in Fig. 8; but I prefer touse a single fastening, as described, for both plates.

I am also aware of the patent to May and Hooper, No. 97,209, grantedNovember 23, 1869, and I claim nothing therein shown or described. Imake a direct connection between the two metal plates, and the strengthof the slide and its weight-carrying power are only limited by thestrength of the plate; in other words, it is equal to the breakingstrength of the iron. In the old slides it equals the hold of the woodupon the screw-thread, which would vary materially, according to the density of the wood or its fibrous strength. In the best wood, and thatwhich would have the strongest hold on the screw, it is difficult todrive the screw without boring so near to the size of the screw itselfas to reduce the cut of the thread into the wood and so lessen its hold.If the wood were not bored, alarge number of screw-heads would bebroken, which would involve the taking out of the screw, the reaming ofthe hole, and the insertion of a new screw. In the former case (as thewoods must be bored alike, and as they vary greatly as to strength,toughness, and density) there will be an appreciablepercentage of brashpieces, in which, with a hole so bored, the hold of the screwwill bemerely nominal. With my slide all pieces can be used with equal safety.Moreover, if a screw gives out in the old slide the table will breakdown, whereas if the plate breaks in my slide, which is the worst thatcould happen, its running capacity only is destroyed, for the nut on theend of the bolt will hold the parts in position under any test that atable will be put to. The slide with one bolt can be made cheaper thanthe slide with four screws, (one bolt answering the purpose of thatnumber of screws) and owing to the greater strength given by thebolt-fastening the sections can he made with less lap, consequentlyfewer sections to a table, and as a result a cheaper article thanheretofore, and at the same time; a better one.

I claim as my invention 1. The combination, with the bar A, having thegrooves B, of the plates 0, having the ribs D, sliding in the grooves B,and having the bearing-flanges G, extending beyond the edge of theplate, whereby a bearing is provided the edge of the plate, whereby abearing is provided upon both sides of the groove B, substantially asset forth.

3. As a new article of manufacture, the extension-table slide consistingof the metallic plate G, having at its opposite edges upon the same sidethe projecting ribs D D, and the bearing-flanges G at one edge of theplate, with a hole through the plate near the rib D, substantially asdescribed.

In testimony whereof I have hereunto set my hand this 23d day of July,1886.

HENRY O. HALL.

In presence of A. 0. PAUL, B. .H. SANFORD.

